Level and Timing of Nitrogen Fertilizer Application to Early and Semi-early Potatoes (Solanum tuberosum L.) Grown with Irrigation on Light Soils in Norway

Trials were performed with early and semi-early potatoes to test the effects of nitrogen (N) fertilizer level (0-160 kg N ha^-1) and timing (all at planting versus half then and half either soon after emergence or 3 weeks later). All seven trials with earlies were irrigated as required, whilst different irrigation regimes (moderate versus intensive) were compared in two trials with semi-earlies. No benefit was derived from splitting the N application. Haulm growth and N uptake increased in all cases almost linearly up to the highest N level, but tuber yield did not respond in the same way. The optimum N level was 80 kg N ha^-1 for a yield of 15 Mg ha^-1, rising to 120 kg N ha^-1 for a yield of 40 Mg ha^-1. Tuber quality was lowered by the use of excess N fertilizer, particularly in the case of earlies. The quantity of mineralised N present in the soil after harvest rose sharply with above optimum fertilizer use, and the amount of N present in crop residues also increased. The likely leaching after early potatoes was estimated to be up to 80 kg N ha^-1. The proportion of fertilizer N which was not accounted for in either tuber yield, crop residues or mineral N in soil was 26% in earlies and 38% in semi-earlies.     

药用红花生长发育规律的研究

根据药用红花根、叶、茎、分枝、花及生长中心的变化特点，将药用红花个体发育过程划分为莲座期、伸长期、分枝期、开花期及种子成熟期５个生育时期，红花一生有５２叶左右，以伸长期出叶速度最快，平均每２．０天出一叶，这一时期形成１７叶左右。叶面积在生育前期较小，至分枝期达最高值（４月中旬，３０７４．５ｃｍ＾２／ｐｉａｎｔ，叶面积指数５．５），且保持较高叶面积一定时间，以利于分枝和花的发育。红花在分枝期净同化率     

旱作多功能精密穴播轮的研究

通过旱作多功能精密穴播轮工作机理的研究,建立了容种、充种、清种、成穴过程相关数学模型,揭示了穴播轮转速、容种高度对播种质量的影响规律。     

用交流电焊机干燥低压电动机

介绍了用交流电焊机干燥中小型低压电动机的方法，实际应用表明，该方法操作方便、安全，适用范围广泛。     

婴幼儿配方奶粉研究进展

婴幼儿配方奶粉是非母乳喂养婴儿最重要的营养来源,我国婴幼儿配方奶粉市场需求巨大,但基础营养与加工技术研究起步较晚。本文从母乳营养需求、配方奶粉标准和奶粉基料研发等方面,详细介绍了婴幼儿配方奶粉的营养学研究进展;从干法与湿法等生产工艺对配方奶粉特性的影响方面论述了婴幼儿配方奶粉加工技术的研究进展;同时也讨论了婴幼儿奶粉中存在的危害风险,为我国婴幼儿配方奶粉在基料选择、生产技术和产业发展方面提供参考。     

稻草与氨化稻草干物质采食量的模型化研究

本研究分别以稻草、氨化稻草为唯一能量和蛋白质来源,实测了山羊稻草、氨化稻草的干物质采食量(DMI),并借鉴现有成熟模型,建立了以稻草、氨化稻草的中性洗涤纤维(NDF)为预测因子的干物质采食量预测模型:DMI稻(g/d.kgMW)=30/NDF(%DM),DMI氨稻(g/d.kgMW)=39/NDF(%DM)。经验证,稻草、氨化稻草DMI预测模型的平均偏差(MD)分别为0.48g/d.kgMW与0.85g/d.kgMW,相应的平均预测方差(MSPE)为0.3599与1.0124。稻草与氨化稻草的MD、MSPE均很低,表明所建DMI预测模型精确可用。     

The growth of tagestes erecta,petunia hybrida nana compacta and myosotis alpestris in a range of peat‐based container media

Abstract

The dry matter yield and nitrogen content of marigold (Tagestes erecta), petunia (Petunia hybrida nana compacta) and forget‐me‐not (Myosotis alpestris) plants growing in a range of peat‐based container media amended with different proportions of either sand, perlite, pumice, sawdust, bark chips or soil were studied under glasshouse nursery conditions.

Plant responses differed between species as manifested by their different correlations with measured moisture and aeration characteristics of the media. Marigold and petunia were adversely affected by excessive moisture content as demonstrated by their negative correlation with micropore water and container capacity. However, forget‐me‐not, being adapted to relatively high moisture regimes, responded adversely to increased aeration.     

宁夏旱作农业区应用全膜双垄沟播技术的效应分析

摘要：通过对宁夏旱作农业区应用全膜双垄沟播技术效应、存在问题的分析，肯定了该项技术是旱作农业的一项突破性技术，针对其在生产应用中存在的技术问题，提出了提高认识、强化技术培训、提高技术到位率、加强技术创新力度、坚持地膜补贴惠民政策、建立旧膜回收机制、加强领导等对策，以加快全膜双垄沟播技术的应用速度，发挥更大的增产、增效作用。     

心里美萝卜生长动态及养分吸收规律

对心里美萝卜生长动态及氮、磷、钾、硫吸收规律的研究结果表明：植株鲜重、干重以出苗后６１～７５天增长最快;肉质根产量在６５５８９ｋｇ／ｈｍ２时,平均每生产１０００ｋｇ肉质根,植株需吸收Ｎ２．１１９ｋｇ、Ｐ２Ｏ５１．３０６ｋｇ、Ｋ２Ｏ２．４５１ｋｇ、Ｓ０．５８９ｋｇ,比例为１．００∶０．６２∶１．１６∶０．２８;出苗后３１～７５天是植株吸收养分的主要时期;收获时植株吸收的各种养分主要贮存在肉质根内。